We have been trying to make our Document Server work behind an Apache Proxy server. We faced an error stating "WebSocket connection to 'wss://document-server/doc/-731460377/c/244/okvazqnd/websocket' failed: Error during WebSocket handshake: Unexpected response code: 400".As a work around we used " ProxyPassMatch "^/(.*\websocket)$" "ws://document-server/$1" " and it started working.Is websocket the correct and only identifier for ws traffic?